FBI agents are not paid in hourly wages, they are paid through the federal government system GS ratings which provides agents an annual salary rating for years served.
The tariff of the United States, like all actual protective tariffs, is partly revenue and partly protective, its original purpose of yielding revenue having been subordinated to that of giving protection, until it may now be best described as a protective tariff yielding incidental revenue.
A tariff is a tax placed on imported goods. Each country has separate regulations, but there are five main types of tariffs: revenue, ad valorem, specific, prohibitive and protective. A revenue tariff increases government funds. For example, countries that do not grow bananas may create a tax on importing bananas.